How do pregnancy tests work? - Tien Nguyen
View full lesson: http://ed.ted.com/lessons/how-do-pregnancy-tests-work-tien-nguyen Over-the-counter pregnancy tests give potentially life-changing results with a pretty high rate of accuracy....
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The earliest known pregnancy test dates back to 1350 BC in Ancient Egypt. According to the Egyptians, all you have to do is urinate on wheat and barley seeds, and wait. If either sprouts, congratulations, you're pregnant! And if wheat sprouts faster, it's a girl, but if barley, it's a boy. In 1963, a small study reproduced this test and found that it predicted pregnancy with a respectable 70% accuracy, though it couldn't reliably tell the sex of the baby. Scientists hypothesized that the test worked because pregnant women's urine contains more estrogen, which can promote seed growth. Now it's easy to take this ancient method for granted because modern pregnancy tests give highly accurate results within minutes. So how do ...
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The earliest known pregnancy test dates back to 1350 BC in Ancient Egypt. According to the Egyptians, all you have to do is urinate on wheat and barley seeds, and wait. If either sprouts, congratulations, you're pregnant! And if wheat sprouts faster, it's a girl, but if barley, it's a boy. In 1963, a small study reproduced this test and found that it predicted pregnancy with a respectable 70% accuracy, though it couldn't reliably tell the sex of the baby. Scientists hypothesized that the test worked because pregnant women's urine contains more estrogen, which can promote seed growth. Now it's easy to take this ancient method for granted because modern pregnancy tests give highly accurate results within minutes. So how do ...
